Feeding a combination of lactate-utilizing and lactate producing bacteria modulates acute phase response in feedlot steers

Abstract

Six ruminally cannulated steers were used in a replicated 3 × 3 Latin square with 2 wk for adaptation and 1 wk for measurements to study the effects of Propionibacterium P15 (P15) alone or in combination with Enterococcus faecium EF212 (PE) on acute phase response. Treatments were: (i) carrier (control), (ii) P15, and (iii) PE. The bacterial treatments [109 colony forming units (CFU) d-1] mixed in whey powder (carrier), or whey powder alone for control animals, were top-dressed once daily at the time of feeding (10 g steer-1 d-1). Blood samples were obtained from jugular veins on the last day of each period at 0, 6, and 12 h after feeding of bacteria and serum amyloid A (SAA), haptoglobin, lipopolysaccharide de-binding protein (LBP) were measured by ELISA and alpha1-acid glycoprotein (α1-AGP) by radial immunodiffusion. Results indicate that feeding P15 alone increased SAA and lowered plasma haptoglobin, whereas, feeding PE elevated concentrations of SAA, but had no effect on plasma haptoglobin. No significant differences were obtained for plasma α1-AGP among the experimental groups. In conclusion, feeding direct-fed microbials induced an inflammatory response in feedlot steers. Key words: Acute phase response, feedlot steers, direct-fed microbials